The present invention relates generally to dental prostheses, and more particularly, to an attachment device for removable partial dentures and a method of affixing the attachment device within an oral cavity.
In the replacement of several teeth within the mouth, it is often desirable to use a removable partial denture. The removable partial denture is indicated where the arrangement of remaining teeth in the oral cavity cannot support a fixed partial denture. To be retained in position while in use in the wearer's mouth, the partial bridge must be anchored in some manner within the mouth, and is generally removably attached to the remaining teeth.
In the past, two basic types of anchoring attachments have been used. First, extracoronal attachments on the denture, such as clasps, have been used to grip around remaining, abutting natural teeth. In this type of attachment, clasps are provided on the portion of the partial denture closest to the remaining teeth when mounted. In use, the clasps tightly grip the abutment teeth to maintain the connection between the partial denture and abutment teeth, and hold the denture in place. This type of attachment, however, has a particularly unsatisfactory cosmetic appearance, as the clasps, which wrap around the abutment teeth, are visible and unsightly. As an alternative to such extracoronal attachments, many intracoronal attachments have been proposed and used. This type of attachment requires a first member, to be permanently affixed to an abutment tooth, and a complementary second member, releasably interlockable with the first member, mounted on the partial denture. The connecting members are mounted on the partial denture. The connecting members are mounted in their respective positions, generally in close relationship, on abutting surfaces of the abutment tooth and partial denture. This type of connector is much more cosmetically acceptable but the attachment of an extracoronal attachment connector member to the abutment tooth is a difficult procedure. This type of attachment has heretofore required the construction of a crown over the abutment tooth. To make such a crown requires that an otherwise healthy tooth be ground down and reduced in size so that a crown containing the appropriate connector member may be cemented on the remains of the tooth to support the connector member and replace, cosmetically and functionally, the now-destroyed tooth.
The described procedure results in the destruction of an otherwise healthy tooth. Installation of intracoronal attachments is considered a costly and difficult type of dental treatment. Once completed, the destroyed tooth structure cannot be recovered. Additionally, the crowned tooth is still not as cosmetically appealing as an intact natural tooth.
Recent work in the area of fixed partial dentures and tooth replacement has resulted in a new type of restorative method, known as the Acid Etched Resin Bonded Retainer Technique. This method of restoration involves the resin bonding of a framework carrying replacement teeth, to abutting teeth, with a minimum of tooth removal. Thus, fixed partial denture bridges may be permanently attached to the remaining teeth, without the use of crowns, and the concurrent destruction of healthy teeth.